Which of the following is not a coelentrate ?

Options

A. sea star
B. sea lily
C. sea star
D. All of the above

Answer

To determine which of the following is not a coelenterate, we need to understand the characteristics of coelenterates and compare them with the given options.

### Step-by-Step Solution:

1. **Identify Coelenterates**: Coelenterates, also known as Cnidarians, belong to the phylum Cnidaria. They include organisms such as jellyfish, corals, and sea anemones. A key feature of coelenterates is the presence of specialized cells called cnidocytes, which contain stinging structures known as nematocysts.

2. **Review the Options**: The question typically provides a list of organisms. We need to analyze each option to see if it belongs to the phylum Cnidaria or not.

3. **Recognize Echinoderms**: Echinoderms, such as starfish (Asteroidea), sea lilies (Crinoidea), and others, belong to a different phylum (Echinodermata). They have a unique water vascular system and do not possess nematocysts.

4. **Compare Features**: Since coelenterates lack a water vascular system and possess nematocysts, any organism that has these features (like echinoderms) is not a coelenterate.

5. **Conclusion**: After analyzing the options, if all the provided examples are echinoderms, then none of them are coelenterates. Therefore, the answer to the question is that all the options listed are not coelenterates.

### Final Answer:
All of the above options are not coelenterates.